Information recording medium, information recording method, information recording apparatus, information reproduction method, and information reproduction apparatus

ABSTRACT

According to a recording method for a conventional rewritable disc, the latest data is recorded by rewriting data in an identical area. In the case of a disc of which the number of times of data rewrite is limited, this causes a problem that a defect block is easily generated. The present invention has an objective of providing an information recording medium, an information recording and reproduction method, and an information recording and reproduction system apparatus, by which data is recorded sequentially from an unallocated area after an entry sector number, and data recording is sequentially repeated from an inner portion to an outer portion.

This application is a divisional of U.S. patent application Ser. No.10/333,662 filed on Jan. 21, 2003, which is hereby incorporated hereinby reference in its entirety, which is based on PCT InternationalApplication No. PCT/JP02/07688, filed on Jul. 29, 2002, which claimspriority to Japan Patent Application Nos. 2001-234537, filed Aug. 2,2001; 2001-245088, filed Aug. 10, 2001; 2001-262,479, filed Aug. 30,2001; 2001-277306, filed Sep. 12, 2001; 2001-292593, filed Sep. 25,2001; and 2001-346779, filed Nov. 12, 2001.

TECHNICAL FIELD

The present invention relates to an information recording medium, ofwhich the number of times data can be rewritten in the same area islimited, a method and an apparatus for recording information on such aninformation recording medium, and a method and an apparatus forreproducing information recorded on such an information recordingmedium.

BACKGROUND ART

One exemplary information recording medium having a sector structure isan optical disc. As the density and capacity of the optical disc haverecently been increased and more and more information has beentransferred by multimedia, video and audio data are now enjoyedinteractively using a plurality of strings of data recorded on anoptical disc. A disc, having interactive video data recorded thereon,has an AV file including a plurality of MPEG streams as well as acontrol file for controlling reproduction of AV data recorded thereon.

Hereinafter, with reference to FIG. 8 illustrating a directorystructure, the relationship of an AV directory structure and an AV filewith a control file will be described. An AV directory at which videoand audio data is recorded is located under a root directory. The AVdirectory has AV files (AVfile-a), (AVfile-c) and (AVfile-d) includingthe video and audio data itself, and a control file (Datafile) includinginformation regarding the AV files. The control file (Datafile)includes, for example, names of titles of video and audio data recordedon the disc, the order of reproduction of data strings of each title,and positional information of I picture, P picture and the like whichare necessary for special reproduction such slow reproduction,fast-forwarding and the like. In the case where one control filecorresponds to one AV file, a plurality of control files may berecorded. The files are recorded under a predetermined directory withpredetermined file names, such that the recording and reproductionapparatus can easily access an intended file.

With reference to FIG. 21, one exemplary data structure of a DVD-RAMdisc, which is a rewritable disc, having the above-described filesrecorded thereon using a volume file structure defined in the ECMA167Standards will be described. An upper portion of the figure correspondsto an inner area of the disc, and a lower portion of the figurecorresponds to an outer area of the disc. Logical sector numbers areallocated from the leading end of the volume space in units of a sector.A volume structure area 101 has information recorded therein forlogically handling the disc as a volume, and also has positionalinformation of a space bit map 1021 and positional information of a fileentry 1022 of a root directory. In general, each file is accessed usinga logical block number, but in this example, each file is accessed usinga logical sector number for simplicity of explanation.

A file structure area 1001 is an area in which a descriptor for defininga file structure is to be recorded. The space bit map 1021 is a bit mapfor managing, in units of a sector, an unallocated area of the volumespace to which a file structure or data can be allocated. The space bitmap 1021 has information indicating, in units of a logical sector,whether each area has information already recorded therein orunallocated. The file entry (root directory) 1022 has attributeinformation and recording position information of a root directory. Aroot directory 1023 has positional information of an file entry 1024 ofan AV directory (AVDir) recorded under the root directory.

The file entry (AVDir) 1024 has attribute information and recordingposition information of an AV directory (AVDir) 1025. The AV directory(AVDir) 1025 has positional information of file entries 1026, 1027, 1028and 1029 respectively of an AV file (AVfile-a), an AV file (AVfile-c),an AV file (AVfile-d) and a control file (Datafile).

These file entries of the AV files and the control file have attributeinformation and positional information of the AV file (AVfile-a), the AVfile (AVfile-c), the AV file (AVfile-d) and the control file (Datafile)1030 which are recorded in a file area 1002. The file area 1002 is anarea in which data of the AV files and the control file is to berecorded.

A defect management area 1003 includes a DMA (Defect Management Area)1004 for managing a defect and a spare area 1005 in which the content ofthe data which is to be recorded in the defect area is substitutivelyrecorded. In the DMA, a spare entry for managing a defect area which issubstituted for and an area for substituting for the defect area isregistered. The spare entry has an address 1045 of the defect area andan address 1046 of the spare area.

Next, with reference to FIG. 22 illustrating a block diagram and FIG. 23illustrating a flowchart, a process for writing new video and audio dataover the AV file (AVfile-d) will be described. Here, the size of thevideo and audio data to be newly written is larger than the size of thevideo and audio data already recorded in the AV file (AVfile-d).

(S1201) A system control section 201 follows a control program builttherein as file structure reproduction means 110 so as to acquirepositional information of an unallocated area corresponding to the sizethat the AV file (AVfile-d) is short of, and necessary for, writing thenew video and audio data from the space bit map 1021.

(S1202) The system control section 201 follows a control program builttherein as file recording means 213 so as to overwrite the data in theAV file (AVfile-d), and instructs an optical disc drive device 205 torecord data in the unallocated area acquired in step (S1201). Theoptical disc drive device 205 records the video and audio datatransferred from a data memory 221 and writes the relevant control dataover the data in the control file (Datafile). When a defect area isdetected during the file recording processing, the optical disc drivedevice 205 substitutively records the content of the AV file, which isto be recorded in a defect area 1053, in the spare area 1005, andregisters, in the DMA 1004, a spare entry 1051 which is informationcorresponding to an address 1045 of the defect area 1053 and an address1046 of the spare area 1005. The optical disc drive device 205 notifiesthe system control section 201 of the completion of the recordingoperation.

(S1203) The system control section 201 follows a control program builttherein as file structure recording means 1101 so as to reflect therecording state of the unallocated area, used in step (S1202), in thespace bit map 1021.

(S1204) The system control section 201 follows a control program builttherein as the file structure recording means 1101 so as to instruct theoptical disc drive device 205 to record in the file structure area 1001the updated space bit map 1021, the file entry (Datafile) 1029 of thecontrol file (Datafile) 1030, and the file entry (AVfile-d) 1028 of therecorded AV file. The optical disc drive device 205 writes such filestructures transferred from a file structure memory 1103 over the datain the file structure area, and notifies the system control section 201of the completion of the recording operation.

In the above example of substituting for a defect area, the AV file isoverwritten. The substituting is similarly performed for recording adata file such as a control file, a volume structure or a filestructure.

In a lead-in area of the DVD-RAM disc, four data structure area DMAs(Defect Management Areas) for defect management performed in a sector inthe volume space are provided. All such DMAs are rewritten at thecorresponding position each time a defect occurs.

For simplicity of explanation, the spare area is located in the lead-inarea in the above example. In an actual DVD-RAM disc, however, a sparearea is provided between the lead-in area and the volume space. In thecase where there is a shortage of the spare area due to frequentoccurrence of substitution, an additional spare area is provided in anarea external to the volume space.

In the case of a rewritable disc in which data can be rewritten in thesame sector 100,000 times, no problem occurs even if data isconcentratedly rewritten in the same sector. In the case of a rewritabledisc to which the number of times data can be rewritten is limited toabout 100 to 1000 times, however, the following problems occur when theuser newly creates, rewrites, or deletes a file: since data isfrequently written in the same area, defects easily occur as a result ofwhich important data, such as a file structure or a control file, isdestroyed, or data cannot be recorded on the medium.

The present invention for solving the above-described problems has anobjective of sequentially moving an AV file area and a basic filestructure area from an inner portion to an outer portion of a disc towhich the number of times of data rewrite is limited, so as to avoidconcentration of data rewrite in the same area and thus preventoccurrence of a defect.

DISCLOSURE OF THE INVENTION

An information recording medium, according to the present invention, ofwhich the number of times of data rewrite to an identical area islimited includes an information recording area to which sequential looprecording is to be performed; and a pointer information recording areafor recording pointer information indicating a position of an end of anarea in which data has been recorded by a previous recording operationto the information recording area. Thus, the above-described objectivesare achieved.

The information recording area may include an AV file recording area forrecording an AV file.

The information recording area may include an area for recording a spacemanagement structure for managing an unallocated area in the informationrecording area.

An information recording medium, according to the present invention, ofwhich the number of times of data rewrite to an identical area islimited includes an information recording area to which sequential looprecording is to be performed; and a pointer information recording areafor recording pointer information indicating a position of an area whichhas been allocated by a previous recording operation to the informationrecording area. Thus, the above-described objectives are achieved.

The information recording area may include an area for recording a filestructure.

The information recording area may include an area for recording a spacemanagement structure for managing an unallocated area in the informationrecording area.

An information recording medium, according to the present invention, ofwhich the number of times of data rewrite to an identical area islimited, includes a first information recording area to which sequentialloop recording is to be performed; a second information recording areato which sequential loop recording is to be performed; a first pointerinformation recording area for recording first pointer informationindicating a position of an area which has been allocated by a previousrecording operation to the first information recording area, and asecond pointer information recording area for recording second pointerinformation indicating a position of an area in which data has beenrecorded by a previous recording operation to the second informationrecording area. The second pointer information recording area isprovided in the first information recording area. Thus, theabove-described objectives are achieved.

The second information recording area may include an AV file recordingarea for recording an AV file. The first information recording area mayinclude a management information area for recording managementinformation for managing the AV file recording area.

A defect area in the management information area may be managed inaccordance with a first defect management method. A defect area in theAV file recording area may be managed in accordance with a second defectmanagement method which is different from the first defect managementmethod.

The first defect management method may be based on recording withverify, and the second defect management method is based on recordingwithout verify.

The second information recording area may include an AV file recordingarea for recording an AV file. The first information recording area mayinclude a non-AV file recording area for recording a non-AV file.

An information recording medium, according to the present invention, ofwhich the number of times of data rewrite to an identical area islimited, includes a first information recording area to which sequentialloop recording is to be performed; and a second information recordingarea, allocated to a part of the first information recording area, towhich sequential loop recording is to be performed. The informationrecording medium is structured so as to allow a position of the secondinformation recording area to be moved in the first informationrecording area. Thus, the above-described objectives are achieved.

An information recording method, according to the present invention, forrecording information on an information recording medium of which thenumber of times of data rewrite to an identical area is limited isprovided. The information recording medium includes an informationrecording area to which sequential loop recording is to be performed,and a pointer information recording area. The information recordingmethod includes the steps of performing a recording operation to theinformation recording area repeatedly; and recording, in the pointerinformation recording area, pointer information indicating a position ofan end of an area in which data has been recorded by a previousrecording operation to the information recording area. Thus, theabove-described objectives are achieved.

The information recording method may further include the step ofsearching for an unallocated area in the information recording area in acertain direction from a position subsequent to the position indicatedby the pointer information.

An information recording method, according to the present invention forrecording information on an information recording medium of which thenumber of times of data rewrite to an identical area is limited isprovides. The information recording medium includes an informationrecording area to which sequential loop recording is to be performed,and a pointer information recording area. The information recordingmethod includes performing a recording operation to the informationrecording area repeatedly; and recording, in the pointer informationrecording area, pointer information indicating a position of an areaallocated by a previous recording operation to the information recordingarea. Thus, the above-described objectives are achieved.

The information recording method may further include the step ofsearching for an unallocated area in the information recording area in acertain direction from a position subsequent to the position indicatedby the pointer information.

An information recording method, according to the present invention, forrecording information on an information recording medium of which thenumber of times of data rewrite to an identical area is limited isprovided. The information recording medium includes a first informationrecording area to which sequential loop recording is to be performed, asecond information recording area to which sequential loop recording isto be performed, a first pointer information recording area, and asecond pointer information recording area, wherein the second pointerinformation recording area is provided in the first informationrecording area. The information recording method includes the steps ofperforming a recording operation to the first information recording arearepeatedly; recording, in the first pointer information recording area,first pointer information indicating a position of an area allocated bya previous recording operation to the first information recording area;performing a recording operation to the second information recordingarea repeatedly; and recording, in the second pointer informationrecording area, second pointer information indicating a position of anarea in which data has been recorded by a previous recording operationto the second information recording area. Thus, the above-describedobjectives are achieved.

The information recording method may further include the steps ofsearching for an unallocated area in the first information recordingarea in a certain direction from a position subsequent to the positionindicated by the first pointer information; and searching for anunallocated area in the second information recording area in a certaindirection from a position subsequent to the position indicated by thesecond pointer information.

An information recording method, according to the present invention, forrecording information on an information recording medium of which thenumber of times of data rewrite to an identical area is limited isprovided. The information recording medium includes a first informationrecording area to which sequential loop recording is to be performed,and a second information recording area to which sequential looprecording is to be performed. The information recording method includesthe steps of allocating the second information recording area to a partof the first information recording area; and moving a position of thesecond information recording area, allocated to the part of the firstinformation recording area, in the first information recording area.Thus, the above-described objectives are achieved.

An information recording apparatus, according to the present invention,for recording information on an information recording medium of whichthe number of times of data rewrite to an identical area is limited isprovided. The information recording medium includes an informationrecording area to which sequential loop recording is to be performed,and a pointer information recording area. The information recordingapparatus includes means for performing a recording operation to theinformation recording area repeatedly; and means for recording, in thepointer information recording area, pointer information indicating aposition of an end of an area in which data has been recorded by aprevious recording operation to the information recording area. Thus,the above-described objectives are achieved.

The information recording apparatus may further include means forsearching for an unallocated area in the information recording area in acertain direction from a position subsequent to the position indicatedby the pointer information.

An information recording apparatus, according to the present invention,for recording information on an information recording medium of whichthe number of times of data rewrite to an identical area is limited isprovided. The information recording medium includes an informationrecording area to which sequential loop recording is to be performed,and a pointer information recording area. The information recordingapparatus includes means for performing a recording operation to theinformation recording area repeatedly; and means for recording, in thepointer information recording area, pointer information indicating aposition of an area allocated by a previous recording operation to theinformation recording area. Thus, the above-described objectives areachieved.

The information recording apparatus may further include means forsearching for an unallocated area in the information recording area in acertain direction from a position subsequent to the position indicatedby the pointer information.

An information recording apparatus, according to the present invention,for recording information on an information recording medium of whichthe number of times of data rewrite to an identical area is limited isprovided. The information recording medium includes a first informationrecording area to which sequential loop recording is to be performed, asecond information recording area to which sequential loop recording isto be performed, a first pointer information recording area, and asecond pointer information recording area, wherein the second pointerinformation recording area is provided in the first informationrecording area. The information recording apparatus includes means forperforming a recording operation to the first information recording arearepeatedly; means for recording, in the first pointer informationrecording area, first pointer information indicating a position of anarea allocated by a previous recording operation to the firstinformation recording area; means for performing a recording operationto the second information recording area repeatedly; and means forrecording, in the second pointer information recording area, secondpointer information indicating a position of an area in which data hasbeen recorded by a previous recording operation to the secondinformation recording area. Thus, the above-described objectives areachieved.

The information recording apparatus may further include means forsearching for an unallocated area in the first information recordingarea in a certain direction from a position subsequent to the positionindicated by the first pointer information; and means for searching foran unallocated area in the second information recording area in acertain direction from a position subsequent to the position indicatedby the second pointer information.

An information recording apparatus, according to the present invention,for recording information on an information recording medium of whichthe number of times of data rewrite to an identical area is limited isprovided. The information recording medium includes a first informationrecording area to which sequential loop recording is to be performed,and a second information recording area to which sequential looprecording is to be performed. The information recording apparatusincludes means for allocating the second information recording area to apart of the first information recording area; and means for moving aposition of the second information recording area, allocated to the partof the first information recording area, in the first informationrecording area. Thus, the above-described objectives are achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a data structure of an information recording mediumaccording to Example 1.

FIG. 2 is a block diagram illustrating a structure of an informationrecording and reproduction apparatus according to Example 1.

FIG. 3 is a flowchart illustrating a procedure of formatting processingin Example 1.

FIG. 4 shows a data structure of an information recording medium afterthe formatting processing is performed in Example 1.

FIG. 5 is a flowchart illustrating a procedure of file recordingprocessing in Example 1.

FIG. 6 shows a data structure of an information recording medium afterthe file recording is performed in Example 1.

FIG. 7 is a flowchart illustrating a procedure of file reproductionprocessing in Example 1.

FIG. 8 shows a directory structure for managing a file recorded on adisc.

FIG. 9 shows a data structure of a recording information zone in Example1.

FIG. 10 shows a data structure of an information recording medium havinga plurality of entry sector numbers in Example 1.

FIG. 11 shows a data structure of an information recording mediumaccording to Example 2.

FIG. 12 shows a data structure of an information recording medium aftersubstitution processing to a unit is performed in Example 2.

FIG. 13 is a flowchart illustrating a procedure of file recordingprocessing in Example 2.

FIG. 14 is a flowchart illustrating a procedure of file reproductionprocessing in Example 2.

FIG. 15 shows a data structure of an information recording mediumaccording to Example 3.

FIG. 16 is a flowchart illustrating a procedure of file recordingprocessing in Example 3.

FIG. 17 shows a data structure of an information recording mediumaccording to Example 4.

FIG. 18 is a flowchart illustrating a procedure of file recordingprocessing in Example 4.

FIG. 19 shows a data structure of an information recording mediumaccording to Example 5.

FIG. 20 is a flowchart illustrating a procedure of update processing ofan entry sector number in Example 5.

FIG. 21 shows a data structure of a conventional DVD-RAM disc.

FIG. 22 is a block diagram illustrating a structure of an informationrecording and reproduction apparatus using a conventional DVD-RAM disc.

FIG. 23 is a flowchart illustrating a procedure of conventional filerecording processing.

BEST MODE FOR CARRYING OUT THE INVENTION

(Definition of Terms)

The terms used in this specification will be defined as follows.

(1) “Sequential loop recording” refers to searching for unallocatedareas in a predetermined recording area, allocating the areas based onthe search result, and recording data in the allocated areas. Searchingfor unallocated areas in the predetermined recording area is achieved bysearching for an unallocated area in a certain direction from apredetermined position and, in the case where the search reaches thetrailing end of the predetermined recording area, searching for the nextunallocated area from the leading end of the predetermined recordingarea. In this specification, “sequential loop recording” is alsoreferred to as “loop recording in a certain direction”. These terms aresynonymous.

(2) “AV data” refers to data indicating at least one of video data andaudio data.

(3) An “AV file” refers to a file including AV data.

1. EXAMPLE 1

In Example 1, an information recording medium, of which the number oftimes data can be rewritten in the same area is limited, a method and anapparatus for recording information on such an information recordingmedium, and a method and an apparatus for reproducing informationrecorded on such an information recording medium will be described.

This example assumes an information recording medium to which the numberof times data can be rewritten is limited to about 100 to 1000 times.The present invention is also applicable to an information recordingmedium to which the number of times data can be rewritten is limited toa smaller number of times or a larger number of times. The informationrecording medium may be, for example, any type of information recordingmedium (for example, an optical disc, a magnetic disc, or amagneto-optical disc) In this example, the information recording mediumis an optical disc.

In this example, information to be recorded on the information recordingmedium or information to be reproduced from the information recordingmedium is a file managed using a file structure based on the UDF(Universal Disk Format) conforming to the ECMA167 Standards.

In the following description, a descriptor, a pointer and the like whichare recorded on the information recording medium as a volume filestructure have a data structure defined by the ECMA167 or UDF (UniversalDisk Format) Standards unless otherwise described in detail.

1.1 Data Structure of an Optical Disc

FIG. 1 shows an exemplary data structure of an optical disc.

The optical disc has a lead-in area, a volume space, and a lead-out areaformed thereon. The lead-in area is provided in an inner portion of theoptical disc. The lead-out area is provided in an outer portion of theoptical disc. The volume space is interposed between the lead-in areaand the lead-out area.

The lead-in area has a recording information zone 111 allocated thereto.The recording information zone 111 includes a count unit and a pluralityof registration units.

The volume space has a volume structure area 101, a latest filestructure area 131, and AV file areas 102, 103 and 105 allocatedthereto. Unallocated areas 121, 122, 124 and 125 are areas having novalid data allocated thereto.

The lead-out area has an extended recording information zone 112allocated thereto.

1.2 Structure of an Information Recording and Reproduction Apparatus

FIG. 2 shows an exemplary information recording and reproductionapparatus.

The information recording and reproduction apparatus includes a systemcontrol section 201, a memory circuit 202, a magnetic disc device 204,and an optical disc drive device 205. These elements are connected toeach other via an I/O bus 203.

The system control section 201 includes volume structure recording means211 for recording a volume structure, volume structure reproductionmeans 214 for reproducing the volume structure, VAT structure recordingmeans 212 for recording a VAT structure, VAT structure reproductionmeans 215 for reproducing the VAT structure, space management structurerecording means 251 for recording a space management structure, spacemanagement structure reproduction means 252 for reproducing the spacemanagement structure, basic file structure recording means 261 forrecording a basic file structure, basic file structure reproductionmeans 262 for reproducing the basic file structure, file recording means213 for recording file data, file reproduction means 216 for reproducingthe file data, and defect area management means 217. The system controlsection 201 is implemented by, for example, a microprocessor including acontrol program and an arithmetic memory.

The memory circuit 202 includes a data memory 221 for temporarilystoring a file, a VAT structure memory 222 used for arithmetic ortemporary storage of the VAT structure, a space management structurememory 253 used for arithmetic or temporary storage of the spacemanagement structure, a basic file structure memory 263 used forarithmetic or temporary storage of the basic file, a volume structurememory 223 used for arithmetic or temporary storage of the volumestructure, and a defect list memory 224.

The optical disc drive device 205 includes a drive control section 231,a memory circuit 232, and recording and reproduction means 234. Theseelements are connected to each other via an internal bus 233.

The drive control section 231 includes recording information zonerecording means 271 for recording information in the recordinginformation zone, and recording information zone reproduction means 272for reproducing information recorded in the recording information zone.

The memory circuit 232 includes a recording information zone memory 273used for arithmetic or temporary storage of the information to berecorded in the recording information zone, and a buffer memory 241.

The recording and reproduction means 234 records information on anoptical disc 235 or reproduces information recorded on the optical disc235.

The information recording and reproduction apparatus shown in FIG. 2 hasboth a function of recording information on the optical disc 235 and afunction of reproducing information recorded on the optical disc 235.Accordingly, the information recording and reproduction apparatus shownin FIG. 2 can be regarded as an “information recording apparatus” forrecording information on the optical disc 235. In this case, theelements which are not relevant to the function of recording informationon the optical disc 235 may be omitted. Alternatively, the informationrecording and reproduction apparatus shown in FIG. 2 can be regarded asan “information reproduction apparatus” for reproducing informationrecorded on the optical disc 235. In this case, the elements which arenot relevant to the function of reproducing information recorded on theoptical disc 235 may be omitted.

1.3 Formatting Processing

FIG. 3 shows a procedure of formatting processing for formatting theoptical disc 235. The formatting processing is performed by theinformation recording and reproduction apparatus shown in FIG. 2.Hereinafter, the steps shown in FIG. 3 will be described in detail.

(S301) The system control section 201 creates a volume structureincluding pre-designated parameters such as a volume name, and storesthe volume structure in the volume structure memory 223 of the memorycircuit 202. The system control section 201 further instructs theoptical disc drive device 205 to record the volume structure, stored inthe volume structure memory 223, on the optical disc 235. Theabove-described operations of the system control section 201 areachieved by, for example, executing a control program built in thesystem control section 201 as the volume structure recording means 211.The optical disc drive device 205 records the volume structure at apredetermined position of the optical disc 235, and when the recordingoperation is completed, notifies the system control section 201 of thecompletion of the recording operation.

(S302) The system control section 201 creates a basic file structure,and stores the basic file structure in the basic file structure memory263 of the memory circuit 202. The system control section 201 furtherinstructs the optical disc drive device 205 to record the basic filestructure, stored in the basic file structure memory 263, on the opticaldisc 235. The above-described operations of the system control section201 are achieved by, for example, executing a control program built inthe system control section 201 as the basic file structure recordingmeans 261. The optical disc drive device 205 records the basic filestructure at a predetermined position of the optical disc 235, and whenthe recording operation is completed, notifies the system controlsection 201 of the completion of the recording operation.

(S303) The system control section 201 creates a space managementstructure, and stores the space management structure in the spacemanagement structure memory 253 of the memory circuit 202. At thispoint, positional information of an unallocated area 422 is registeredin a space entry 453 in consideration of the capacity of the VATstructure area allocated in step (S304). The system control section 201further instructs the optical disc drive device 205 to record the spacemanagement structure, stored in the space management structure memory253, on the optical disc 235. The above-described operations of thesystem control section 201 are achieved by, for example, executing acontrol program built in the system control section 201 as the spacemanagement structure recording means 251. The optical disc drive device205 records the space management structure at a predetermined positionof the optical disc 235, and when the recording operation is completed,notifies the system control section 201 of the completion of therecording operation.

(S304) The system control section 201 creates a VAT structure, andstores the VAT structure in the VAT structure memory 222 of the memorycircuit 202. The system control section 201 further instructs theoptical disc drive device 205 to record the VAT structure, stored in theVAT structure memory 222, on the optical disc 235. The above-describedoperations of the system control section 201 are achieved by, forexample, executing a control program built in the system control section201 as the VAT structure recording means 212. The optical disc drivedevice 205 records the VAT structure at a predetermined position of theoptical disc 235, and when the recording operation is completed,notifies the system control section 201 of the completion of therecording operation.

(S305) The system control section 201 instructs the optical disc drivedevice 205 to record data in the recording information zone. The drivecontrol section 231 creates a first registration block 176 including anentry sector number (pointer information) indicating the position of thetrailing end of the latest file structure area and a version number(version information) for identifying a valid registration block, storesthe first registration block 176 in the recording information zonememory 273 of the memory circuit 232, and records the first registrationblock 176 at a predetermined position of the optical disc 235. Forexample, the drive control section 231 records the first registrationblock 176 in a first registration unit 142, and records, at the leadingend of the count unit, the count block having the identification numberof the registration unit in which data has been recorded. Theabove-described operations of the drive control section 231 are achievedby, for example, executing a control program built in the drive controlsection 231 as the recording information zone recording means 271. Whenthe recording operation is completed, the optical disc drive device 205notifies the system control section 201 of the completion of therecording operation.

In this example, the recording operation of the registration block andthe recording operation of the count block are performed separately, butthese recording operations may be performed concurrently.

FIG. 4 shows a structure of data recorded on the optical disc 235 afterthe formatting processing is performed.

The volume structure area 101 has the volume structure recorded therein.The volume structure includes a volume recognition sequence 441 havingrecognition information of a volume, a primary volume descriptor 442having attribute information of the volume, a processing systemdescriptor 443 having information for the processing system, a partitiondescriptor 444 having partition information, a logical volume descriptor445 having recognition information of a logical volume, an unallocatedspace descriptor 446 having information of an unallocated area in thevolume space, an terminating descriptor 447 indicating a trailing end ofa basic descriptor sequence, a logical volume integrity descriptor 448having information of an integrity state of the logical volume, and ananchor volume descriptor pointer 449 having information on access startto the volume. The information recorded in the volume structure area isnot limited to the above-described order or types.

In a basic file structure area 432 of a latest file structure area 431,the basic file structure is recorded. The basic file structure includesa file set descriptor 450, a root directory 451, and a file entry (rootdirectory) 452.

In a space management structure area 421 of the latest file structurearea 431, the space management structure is recorded. The spacemanagement structure includes the unallocated space entry 453.

In a VAT structure area 401 of the latest file structure area 431, theVAT structure is recorded. The VAT structure includes a VAT 454 and aVATICB 455. The VAT 454 and the VATICB 455 are data structures definedby the UDF Standards. A recording position of data on an optical disc isindicated using a virtual address in a virtual address space and alogical address in a logical address space. The VAT 454 retains thecorrespondence between virtual addresses and logical addresses. TheVATICB 455 indicates the recording position of the VAT 454. The VATICB455 is allocated to a sector at the trailing end of the area in whichthe data is recorded.

The recording information zone 111 includes a count unit 141 fordesignating the number of a valid registration unit, and a plurality ofregistration units including the first registration unit 142 and asecond registration unit 143. In the count unit 141, only a first countblock 171 indicating the identification number of the first registrationunit 142 is recorded. In the first registration unit 142, the firstregistration block 176 having an entry sector number 464 indicating thepositional information of the latest file structure area 431 isrecorded.

Data is not recorded in the second count block et seq. in the count unit141. Data is not recorded in the second count block et seq. in the firstregistration unit 142. Data is not recorded in the second registrationunit 143 et seq.

1.4 File Recording Processing

FIG. 5 shows a procedure of file recording processing for recording afile on the optical disc 235. The file recording processing is performedby the information recording and reproduction apparatus shown in FIG. 2.Hereinafter, the steps shown in FIG. 5 will be described in detail. Inthe following example, the AV file (AVfile-a), the AV file (AVfile-b),and a control file thereof are recorded on the optical disc 235 havingthe data structure shown in FIG. 4.

(S501) The system control section 201 acquires positional information467 of an unallocated area from the unallocated space entry 453 whichhas been read to the space management structure memory 253. Theabove-described operation of the system control section 201 is achievedby, for example, executing a control program built in the system controlsection 201 as the space management structure recording means 251.

(S502) The system control section 201 allocates the unallocated areabased on the positional information of the unallocated area acquired instep (S501), and instructs the optical disc drive device 205 to recorddata of an AV file (AVfile-a) 641 in the allocated area. The systemcontrol section 201 further creates a file entry (AVfile-a) 642 of theAV file (AVfile-a) 641, stores the file entry in the data memory 221,and instructs the optical disc drive device 205 to record the file entryin an area continuous from the area in which the data of the AV file(AVfile-a) 641 has been recorded. Similarly, the system control section201 instructs the optical disc drive device 205 to record data of an AVfile (AVfile-b) 643 and a file entry (AV file-b) 644 thereof in thecontinuous areas. The above-described operations of the system controlsection 201 are achieved by, for example, executing a control programbuilt in the system control section 201 as the file recording means 213.The optical disc drive device 205 records the above-mentioned data at apredetermined position of the optical disc 235, and when the recordingoperation is completed, notifies the system control section 201 of thecompletion of the recording operation.

(S503) The system control section 201 creates a basic file structure,and stores the basic file structure in the basic file structure memory263 of the memory circuit 202. The system control section 201 furtherinstructs the optical disc drive device 205 to record the basic filestructure, stored in the basic file structure memory 263, on the opticaldisc 235. The above-described operations of the system control section201 are achieved by, for example, executing a control program built inthe system control section 201 as the basic file structure recordingmeans 261. The optical disc drive device 205 records the basic filestructure at a predetermined position of the optical disc 235, and whenthe recording operation is completed, notifies the system controlsection 201 of the completion of the recording operation.

(S504) The system control section 201 creates a space managementstructure, and stores the space management structure in the spacemanagement structure memory 253 of the memory circuit 202. At thispoint, positional information 666 of an unallocated area #1 (623) andpositional information 667 of an unallocated area #2 (621) areregistered in an unallocated space entry 652 in consideration of thecapacity of a VAT structure area 602 allocated in step (S505). Thesystem control section 201 further instructs the optical disc drivedevice 205 to record the space management structure, stored in the spacemanagement structure memory 253, on the optical disc 235. Theabove-described operations of the system control section 201 areachieved by, for example, executing a control program built in thesystem control section 201 as the space management structure recordingmeans 251. The optical disc drive device 205 records the spacemanagement structure at a predetermined position of the optical disc235, and when the recording operation is completed, notifies the systemcontrol section 201 of the completion of the recording operation.

(S505) The system control section 201 creates a VAT structure, andstores the VAT structure in the VAT structure memory 222 of the memorycircuit 202. The system control section 201 further instructs theoptical disc drive device 205 to record the VAT structure, stored in theVAT structure memory 222, on the optical disc 235. The above-describedoperations of the system control section 201 are achieved by, forexample, executing a control program built in the system control section201 as the VAT structure recording means 212. The optical disc drivedevice 205 records the VAT structure at a predetermined position of theoptical disc 235, and when the recording operation is completed,notifies the system control section 201 of the completion of therecording operation.

(S506) The system control section 201 instructs the optical disc drivedevice 205 to record data in the recording information zone. The drivecontrol section 231 creates a second registration block 177 including anentry sector number (pointer information) indicating the position of thetrailing end of the latest file structure area and a version number(version information) for identifying a valid registration block, storesthe second registration block 177 in the recording information zonememory 273 of the memory circuit 232, and records the secondregistration block 177 at a predetermined position (an area continuousfrom the area in which the first registration block 176 has beenrecorded) of the optical disc 235. The above-described operations of thedrive control section 231 are achieved by, for example, executing acontrol program built in the drive control section 231 as the recordinginformation zone recording means 271. When the recording operation iscompleted, the optical disc drive device 205 notifies the system controlsection 201 of the completion of the recording operation.

FIG. 6 shows a structure of data recorded on the optical disc 235 afterthe file recording processing is performed.

The volume structure area 101 has the volume structure recorded therein.The detail of the volume structure is as described with reference toFIG. 4.

An AV file area 601 has the AV file (AVfile-a) 641, a file entry(AVfile-a) 642 thereof, the AV file (AVfile-b) 643, and a file entry(AVfile-b) 644 thereof recorded therein.

In a basic file structure area 632 of a latest file structure area 631,the basic file structure is recorded. The basic file structure includesa control file (Datafile) 645 having information relevant to the AVfiles, a file entry (Datafile) 646 thereof, an AV directory (AVDir) 647,a file entry (AVDir) 648, a file set descriptor 649, a root directory650, and a file entry (root directory) 651 thereof. The AV directory(AVDir) 647 includes positional information of the file entry (AVfile-a)642 of the AV file (AVfile-a) 641 and positional information of the fileentry (AVfile-b) 644 of the AV file (AVfile-b) 643.

The file set descriptor 649, the root directory 650, and the file entry(root directory) 651 are recorded at a new recording position (logicaladdress). By updating a logical address in the VAT 653 describing thecorrespondence between the virtual addresses and the logical addresses,the new recording position can be accessed using the same virtualaddress. For example, the recording position of the file set descriptor649 designated by the logical volume descriptor 445 is designated usinga virtual address. Even when the file set descriptor 649 is recorded ata new recording position (logical address), the new recording positionof the file set descriptor 649 can be accessed by updating the logicaladdress in the VAT 653 describing the correspondence between the virtualaddresses and the logical addresses.

In a space management structure area 622 of the latest file structurearea 631, the space management structure is recorded. The spacemanagement structure includes the unallocated space entry 652.

In the VAT structure area 602 of the latest file structure area 631, aVAT structure is recorded. The VAT structure includes the VAT 653 andthe VATICB 654.

The recording information zone 111 includes the count unit 141 fordesignating the number of a valid registration unit, and a plurality ofregistration units including the first registration unit 142 and thesecond registration unit 143. In the count unit 141, only the firstcount block 171 indicating the identification number of the firstregistration unit 142 is recorded. In the first registration unit 142,the first registration block 176, and the second registration block 177having an entry sector number 663 indicating the positional informationof the latest file structure area 631 are recorded. It is recognizedthat the second registration block 177 is the latest registration blockhaving the valid entry sector number 663, by comparing a version number463 of the first registration block 176 and a version number 662 of thesecond registration block 177.

1.5 Space Management Structure

Hereinafter, with reference to FIG. 1, the space management structurewill be described.

A space management structure is a structure for managing positionalinformation of an unallocated area which is a continuous area existingin the volume space and in which data is recordable. The spacemanagement structure is necessarily recorded after some data is recordedon an optical disc.

An unallocated space entry 155, which is a space management structure,includes a descriptor tag 185 indicating that the entry is anunallocated space entry, and positional information of at least oneunallocated area existing in the volume space (in the example shown inFIG. 1, positional information 186 of an unallocated area #1, positionalinformation 187 of an unallocated area #2, positional information 188 ofan unallocated area #3, and positional information 189 of an unallocatedarea #4).

In order to record latest information while moving the latestinformation from an inner portion to an outer portion of the opticaldisc, positional information of unallocated areas is registered in theunallocated space entry 155, such that the positional information of theunallocated area external to and closest to the latest file structurearea 131 is registered in the innermost portion of the unallocated spaceentry 155 and then the positional information of the unallocated areaexternal to and next closest to the latest file structure area 131 isregistered in the second innermost portion of the unallocated spaceentry 155. When the positional information of the outermost unallocatedarea is registered in the unallocated space entry 155, the positionalinformation of unallocated areas is registered in the unallocated spaceentry 155, such that the positional information of the innermostunallocated area is registered in the next innermost portion of theunallocated space entry 155 and then the positional information of thenext innermost unallocated area is registered in the next innermostportion of the unallocated space entry 155.

In the example shown in FIG. 1, the unallocated area #1 (124) isexternal to and closest to the latest file structure area 131.Accordingly, the positional information 186 of the unallocated area #1(124) is registered in the unallocated space entry 155 as the firstpositional information.

Next, the positional information 187 of the unallocated area #2 (125)located at the trailing end of the volume space is registered in theunallocated space entry 155 as the second positional information. Next,the positional information 188 of the innermost unallocated area #3(121) in the volume space is registered in the unallocated space entry155 as the third positional information. Finally, the positionalinformation 189 of the unallocated area #4 (122) is registered in theunallocated space entry 155 as the fourth positional information. Inthis manner, the positional information of the unallocated areas isregistered in the unallocated space entry 155 in the order of theunallocated area #1 (124), the unallocated area #2 (125), theunallocated area #3 (121), and the unallocated area #4 (122).

By registering the unallocated areas in the unallocated space entry 155in the above-described order and recording the data in the unallocatedareas in the order of registration in the unallocated space entry 155,data can be recorded while moving the latest file structure area on theoptical disc. As a result, concentration of data rewrite in a specificarea can be avoided, and thus occurrence of defects and data destructioncan be prevented.

In the case where the data recorded on the optical disc is deleted oredited, an area which has been used so far becomes unnecessary.Positional information of the area which becomes unnecessary isregistered in the unallocated space entry 155 as positional informationof a new unallocated area. Where in the unallocated space entry 155 thepositional information of the newly registered unallocated area is to belocated is calculated from the positional information of the unallocatedareas already registered in the unallocated space entry 155. As aresult, the positional information of the new unallocated area isinserted at an appropriate position in the unallocated space entry 155.

In this example, the location of registration of the positionalinformation of an unallocated area in the unallocated space entry 155 isdetermined based on the positions of the unallocated areas in the volumespace. Alternatively, at the time when an area becomes unnecessarybecause of deletion of data, the positional information of the areawhich becomes unnecessary may be registered at the trailing end of theunallocated space entry 155 as positional information of a newunallocated area. Still alternatively, the location of registration ofthe positional information of an unallocated area in the unallocatedspace entry 155 may be determined based on the time at which the areawhich becomes unnecessary is recovered as a new unallocated area. Bythis method also, concentration of data rewrite in a specific area canbe avoided.

The method of recording data from an inner portion to an outer portionaccording to the present invention is also applicable to a write oncetype disc.

In FIG. 8, the case where there is one control file for which datareliability is required is described. Alternatively, a plurality ofcontrol files may be recorded on the optical disc. In this case, thecontrol files may be recorded in the basic file structure area or the AVfile area. When the size of the control files is small or when thenumber of the control files is small, the control files are preferablyrecorded in the basic file structure area. The reason is that thecontrol files are easily accessed when recorded in the basic filestructure area. When the size of the control files is large or when thenumber of the control files is large, the control files are preferablyrecorded in the AV file area. The reason is that the size of the latestfile structure area can be kept small in this way. It is clear that byrecording the control files and file entries thereof in the AV filearea, concentration of data rewrite in a specific area at the time ofupdating the control files can be avoided.

It is possible to perform loop recording in a certain direction based onthe recording position information which indicates the next recordingposition designated by the entry sector number. The positionalinformation of the area where data is recordable is acquired from thespace management structure.

1.6 Data Structure of the Recording Information Zone

FIG. 9 shows an exemplary data structure of the recording informationzone 111. In the example shown in FIG. 9, the recording information zone111 includes one count unit and 250 registration units.

The count unit includes 10 count blocks. Each of the 10 count blocks is,for example, formed as an ECC block which is the minimum recording unit.Recorded in one of the 10 count blocks is identification informationwhich indicates which one of the 250 registration units is valid (forexample, the identification number of the registration unit to which theregistration block having the valid entry sector number recorded thereinbelongs). The count unit is used for searching for a valid registrationunit from the 250 registration units. Use of the count unit allows thelatest entry sector number to be acquired by reading only one validregistration unit, without reading all the registration units.

Each count block is rewritten when the identification number of thevalid registration unit is changed. Accordingly, the number of times thecount block is rewritten is extremely small as compared to the number oftimes the registration block is rewritten.

The 10 count blocks included in the count unit are used sequentiallyfrom the leading count block (first count block). One count block isrepeatedly used until the count block becomes unrecordable. The countblock becomes unrecordable for reasons that, for example, data isrewritten by the number of times exceeding the rewritable number oftimes, and the count block is placed in a defect state due to adherenceof dust or the like. When the first count block becomes unrecordable, asecond count block is used. When the second count block becomesunrecordable, a third count block is used. In this manner, each countblock is rewritten until the count block becomes unrecordable. When thecount block becomes unrecordable, the next count block is used.Accordingly, search in the count blocks can be performed at higher speedas the number of times the data has been rewritten is smaller.

Each of the first registration unit through the 250th registration unitincludes 10 registration blocks. Each of the 10 registration blocks isformed as an ECC block which is the minimum recording unit. Each of the10 registration blocks includes an area used for recording a versionnumber (version information) indicating a version of the registrationblock and an area used for recording an entry sector number (pointerinformation) indicating the trailing end of the latest file structurearea.

Each time data is recorded in the latest file structure area, theversion number and the entry sector number are recorded in oneregistration block selected among the first to the tenth registrationblocks in one registration unit. Each time data is recorded in thelatest file structure area, the registration block, in which the versionnumber and the entry sector number are recorded, is changed. Forexample, when the data is recorded for the first time in the latest filestructure area, the version number and the entry sector number arerecorded in the first registration block; and data is recorded for thesecond time in the latest file structure area, the version number andthe entry sector number are recorded in the second registration block.In this manner, the version number and the entry sector number arerecorded in one registration block, sequentially from the firstregistration block to the tenth registration block. After the versionnumber and the entry sector number are recorded in the tenthregistration block, the version number and the entry sector number arerecorded in the first registration block again (data in the firstregistration block is overwritten). Then, again, the version number andthe entry sector number are recorded in one registration block,sequentially from the first registration block to the tenth registrationblock (data in each registration block is overwritten).

By recording the version number and the entry sector number in theregistration blocks one by one in this manner, concentration of datarewrite in a specific registration block can be avoided.

The position indicated by the entry sector number (pointer information)is not limited to the position of the trailing end of the latest filestructure area. The position indicated by the entry sector number(pointer information) may be any position (for example, a predeterminedposition) in any area (for example, the second information recordingarea) on the optical disc 235. The second information recording area maybe an area where data is recordable by sequential loop recording.

In this example, data is sequentially recorded repeatedly in each of the250 registration units. Namely, each of the 250 registration units is anexample of the first information recording area in which data isrecordable by sequential loop recording. By sequentially recording datarepeatedly in each of a plurality of divided areas in this manner, thereliability of all the areas can be improved and the reading speed fromeach area can be raised.

The latest registration block is managed so as to have the largestversion number in the registration unit to which the latest registrationblock belongs. The largest version number indicates the latest versioninformation. The entry sector number (pointer information) correspondingto the largest version number (latest version information) is used asthe valid entry sector number (valid pointer information).

In the example shown in FIG. 9, the third registration block havingversion number (3) is the latest registration block. By causing theregistration unit to include 10 registration blocks in this manner, thelatest registration block can be recognized only by reading data fromthe maximum of 10 registration blocks.

When one or more registration blocks become unusable in one registrationunit, the next registration unit is used. For example, when one or moreregistration blocks become unusable in the first registration unit (orwhen the version number of the registration block reaches a certainvalue in the first registration unit), the second registration unit isused. The valid registration unit is identified by the count unit.Accordingly, it is not necessary to search for all the 250 registrationunits in order to identify the valid registration unit.

By providing a reserve recording information zone, in which a copy ofthe information recorded in the recording information zone 111 isrecorded, in the extended recording information zone 112 shown in FIG.1, the reliability of the recording information zone 111 can be raised.In the case where the entry sector number cannot be read from therecording information zone 111 due to a reading error, the entry sectornumber can be read from the extended recording information zone 112.

The information recording zone 111 need not be provided in the lead-inarea or the lead-out area. The information recording zone 111 may beprovided in, for example, an area internal to the lead-in area.Alternatively, the information recording zone 111 may be provided in thevolume structure area 101. In such cases, the effect of preventingconcentration of data rewrite in a specific sector is provided. Thereason is that the position of the trailing end of the area in which theentry sector number is recorded can be indicated while sequential looprecording is performed.

The number of count blocks is not limited to 10. The number of countblocks may be any number of 1 or greater. The number of registrationblocks is not limited to 10. The number of count blocks may also be anynumber of 1 or greater.

The number of registration units is not limited to 250. The number ofregistration units may be any number of 1 or greater. When the number ofregistration units is 1, the count unit may be omitted, since it is notnecessary to search for the valid registration unit. Namely, therecording information zone may be structured so as to include only oneregistration unit. When, for example, the number of registration blocksis sufficiently large, the recording information zone can be structuredso as to include only one registration unit.

The recording unit in the recording information zone may be a sector,and is not limited to an ECC block.

The optical disc may have identification information pre-recordedthereon which indicates that the recording information zone is allocatedto a predetermined area of the optical disc. This identificationinformation guarantees the high reliability of the optical disc, towhich the number of times of data rewrite is limited, at the time ofshipment of the optical disc. The reason is that by sequentiallyrecording data repeatedly using the recording information zone, thelimitation on the number of times of data rewrite can be compensatedfor.

A write once type disc can be regarded as a disc to which the number oftimes of data rewrite is limited to zero. Use of the above-describedrecording information zone allows high-speed recognition of the validregistration unit and the valid registration block recorded therein evenwhen the number of times of data rewrite is larger. When the number oftimes of data rewrite is still larger so that all the registration unitsin the recording information zone are used, further data rewrite becomespossible by allocating a part of the extended recording information zoneas a recording information zone.

It is also possible to provide a recording information zone having amore appropriate data structure to a write once type disc by increasingthe number of registration blocks in one registration unit or byincreasing the number of count blocks in one count unit. For example, inthe case where the number of count blocks in the count unit is equal tothe number of registration units, the count block can be updated by thesame number of times the registration unit is updated. In the case wherethe number of count blocks in the count unit is larger than the numberof registration units, even when the count block cannot be updated dueto a defect block or the like, the next count block can be used.

In order to avoid concentration of data rewrite in a specific countblock in the count unit, data may be sequentially recorded repeatedly inthe count unit. Namely, the count unit is an example of the thirdinformation recording area in which data is recordable by sequentialloop recording. In this case, each count block included in the countunit includes a version number (version information) indicating theversion of the count block and an identification number (identificationinformation) of the registration unit, like the above-describedregistration block.

The latest count block is managed so as to have the largest versionnumber in the count unit. The largest version number indicates thelatest version information. The identification number (identificationinformation) corresponding to the largest version number (latest versioninformation) is used as the valid identification number (valididentification information) of the valid registration unit.

By sequentially recording data repeatedly to the count unit and eachregistration unit, old information remains in the count block and theregistration blocks. Thus, pre-update information (files) can bemaintained on the optical disc so that the information (files) can beused as backup information.

The above-described recording method is applicable to a write once typedisc as well as a rewritable disc. Therefore, a common recording methodcan be useable for the rewritable disc and the write once type disc.

With the optical disc to which the number of times of data rewrite islimited, the registration blocks in the registration unit may be set tobe usable until the registration block becomes unrecordable, instead ofsequential loop recording being performed. This shortens the readingtime of data from the registration unit. The registration block becomesunrecordable for reasons that, for example, data is rewritten by thenumber of times exceeding the rewritable number of times, and theregistration block is placed into a defect state due to adherence ofdust or the like. When the registration block becomes unrecordable, thenext registration block is used. By using one count block repeatedlyuntil the count block becomes unrecordable and also using oneregistration block repeatedly until the registration block becomesunrecordable, the reading time of data from the count unit can beshortened and the reading time of data from the registration unit canalso be shortened.

1.7 File Reproduction Processing

FIG. 7 shows a procedure of file reproduction processing for reproducinga file recorded on the optical disc 235. The file reproductionprocessing is performed by the information recording and reproductionapparatus shown in FIG. 2. Hereinafter, the steps shown in FIG. 7 willbe described in detail. In the following example, an AV file (AVfile-d)158 is reproduced from the optical disc 235 having the data structureshown in FIG. 1.

The optical disc 235 shown in FIG. 1 is obtained by deleting the AV file(AVfile-b) from the optical disc 235 having the data structure shown inFIG. 6 and recording an AV file (AVfile-c) and an AV file (AVfile-d).

(S701) When detecting that an optical disc is inserted to the opticaldisc drive device 205, the drive control section 231 designates theposition of the first count block 171 in the count unit 141 in therecording information zone 111.

(S702) The drive control section 231 determines whether the designatedcount block in the count unit 141 is in an unrecorded state or not. When“yes”, the processing advances to step (S704); and when “no”, theprocessing advances to step (S703).

(S703) The drive control section 231 designates the position of the nextcount block in the count unit 141.

(S704) The drive control section 231 acquires an identification number(identification information) of a registration block from the last countblock among the count blocks which are not in an unrecorded state.

(S705) The drive control section 231 executes a reproduction operationfrom the leading registration block in the registration unit designatedby the identification number of the registration unit, thereby acquiringa version number (version information).

(S706) The drive control section 231 designates the position of the nextregistration block in the designated registration unit.

(S707) The drive control section 231 executes a reproduction operationfrom the designated registration block. When the designated registrationblock designated in this reproduction operation is in an unrecordedstate, or when the version number recorded in the registration block issmaller than the version number acquired before, the processing advancesto step (S709). Otherwise, the processing advances to step (S708).

(S708) The drive control section 231 designates a position of the nextregistration block in the designated registration unit.

(S709) The drive control section 231 acquires an entry sector numberrecorded in the latest registration block, and stores the entry sectornumber in the recording information zone memory 273.

The operations of the drive control section 231 described in steps(S701) through (S709) are achieved by, for example, a control programbuilt in the drive control section 231 as the information recording andreproduction means 272.

(S710) The system control section 201 acquires the entry sector numberstored in the recording information zone memory 273 of the optical discdrive device 205 as information (pointer information) indicating theposition of the trailing end of the latest file structure area. Thesystem control section 201 instructs the optical disc drive device 205to reproduce a VATICB 157 recorded at the trailing end of the latestfile structure area. The above-described operations of the systemcontrol section 201 are achieved by, for example, executing a controlprogram built in the system control section 201 as the VAT structurereproduction means 215. The optical disc drive device 205 reads theVATICB 157 recorded at the trailing end of the latest file structurearea, and stores the VATICB 157 in the VAT structure memory 222 of thememory circuit 202.

Next, the system control section 201 decodes the positional informationof the VAT included in the read VATICB, follows a similar controlprocedure to that for the VATICB so as to read a VAT 156 recorded in theVAT structure area 108, and stores the VAT 156 in the VAT structurememory 222 of the memory circuit 202.

(S711) The system control section 201 reads a file entry (rootdirectory) 154 and a root directory 153 from a file set descriptor 152while converting the virtual address into a logical address using theVAT acquired in step (S710). The system control section 201 also reads afile entry (AVDir) 151 and an AV directory (AVDir) 150 which arerecorded in the same area as the file entry (root directory) 154 and theroot directory 153, as well as a file entry (Datafile) 149 and a controlfile (Datafile) 148 sequentially. Thus, the recording position of the AVfiles and relevant information is acquired. The above-describedoperations of the system control section 201 are achieved by, forexample, executing a control program built in the system control section201 as the basic file structure reproduction means 261.

(S712) Finally, the system control section 201 executes a read operationof a file entry (AVfile-d) 159 and an AV file (AVfile-d) 158, therebycompleting the file reproduction operation. The above-describedoperation of the system control section 201 is achieved by, for example,executing a control program built in the system control section 201 asthe file reproduction means 216.

In order to avoid data from becoming unreadable due to a reading errorduring reproduction, a copy of the data may be recorded in another area.The latest file structure area which is moved by sequential recordingmay be doubled, and the positional information of the doubled latestfile structure area may be designated in the recording information zone.For example, as shown in FIG. 10, a reserve latest file structure area2103 and a main latest file structure area 2107 may be designated basedon a main entry sector number 2151 and a reserve entry sector number2152 recorded in the registration blocks recorded in the registrationblocks recorded in a reserve recording information zone 2101 and a mainrecording information zone 2102.

There is a possibility that data reproduction becomes impossible due tothe causing of scratches or dust after sequential recording with verifyis performed. In order to allow the latest file to be read even in sucha case, the main latest file structure area 2107 and the reserve latestfile structure area 2103 may be provided in the volume space and thepositional information thereof may be registered in the lead-in area asthe main entry sector number 2151 and the reserve entry sector number2152. Thus, data reproduction reliability is improved.

The information to be recorded in the reserve latest file structure area2103 is basically reserve information of the information to be recordedin the main latest file structure area 2107. A VAT 2145 to be recordedin a VAT structure area 2110 is a correspondence table of the virtualaddresses and the logical addresses of the latest file structurerecorded in the main latest file structure area 2107. By contrast, a VAT2135 to be recorded in a VAT structure area 2106 is a correspondencetable of the virtual addresses and the logical addresses of the latestfile structure recorded in the reserve latest file structure area 2103.

The positional information of the main latest file structure area 2107and the positional information of the reserve latest file structure area2103 may respectively be registered in the main recording informationzone 2102 and the reserve recording information zone 2101 of the lead-inarea as the main entry sector number 2151 and the reserve entry sectornumber 2152. In this case, the reserve recording information zone 2101is an area where reserve information of the information registered inthe main recording information zone 2102 is recorded. The structure andmethod of use of the main or reserve recording information zone aresimilar to those of the recording information zone shown in Example 1.

The positional information of the reserve latest file structure area maybe designated with an offset address from the main entry sector number.The offset address may be designated to be, for example, the main entrysector number−256, the main entry sector number−512, the main entrysector number+256, or main entry sector number+512. The offset value maybe registered in the information recording zone.

Even in the case where the recording information zone is provided in thevolume space instead of the lead-in area, the effect of the presentinvention is clearly provided. The entry sector number may be recordedin, for example, the volume space such as the volume structure area 101.In this case also, substantially the same effect as provided when theentry sector number is recorded in the lead-in area is provided.

The recording position information indicating the next recording startposition, such as the entry sector number, allows data to be recordedrepeatedly in a certain direction such that the areas in which data isrewritten are distributed throughout the information recording area ofthe information recording medium.

Registration of the reserve information of the information recorded inthe main recording information zone may be performed independently inthe main recording information zone 2102 and the reserve recordinginformation zone 2101. In this case, the count block or the registrationblock is recorded using recording with verify so as to avoid defectareas. Therefore, the number of the count block or the registrationblock which is the defect area is different between the main recordinginformation zone 2102 and the reserve recording information zone 2101.

In the reserve recording information zone 2101, copy information may berecorded in the same count block or the same registration block as thosein the main recording information zone 2102. In this case, it is notnecessary to perform recording with verify in the reserve recordinginformation zone 2101. Even in a defect state, recording is executed.

In this example, the information recorded in the reserve latest filestructure area is copy information of the main latest file structure.For shortening the recording time, only the file structure updated fromthe previous time of recording may be recorded in the reserve latestfile structure area. When data is unreadable from the main latest filestructure area, the reserve latest file structure and the previous mainlatest file structure can be used to obtain the backup of the data. Theprevious main latest file structure can be acquired by distinguishingthe previous registration block based on the version number and usingthe entry sector number recorded in the registration block.

As shown in FIG. 10, the latest file structure recorded in the volumespace is doubled. In the case where the positional information of bothof the doubled latest file structure is included in the lead-in area,the robustness of the file structure area which is indispensable torecording and reproduction of the file can be improved in theinformation recording medium, to which the number of times of datarewrite is limited, while performing sequential recording. By recordingdata, without fail, in the recording information zone which is an areadesignated for the positional information of the multiplied latest filestructure area, reproduction reliability of the disc is improved,despite the risk of reproduction becoming impossible due to the causesof scratches or dust.

It is clear that the latest file structure area and the entry sectornumber are both applicable to doubling, tripling and other types ofmultiplication.

In the ECMA167 Standards, the file entry of the AV file is defined as apart of the file structure. In this example, the file entry of the AVfile is recorded in the AV file area for simplicity of explanation.

In the case of an information recording medium on which no AV file isrecorded, a control file may be recorded in the AV file area. Still, theeffect of the present invention is clearly provided. In this case, thecontrol file and the file structure thereof are sequentially recorded inthe volume space.

In this example, a file structure using the VAT structure is recorded inthe latest file structure area. In the latest file structure areadesignated by the entry sector number, a file structure of other filesystems such as a FAT file system or the like may be recorded. Even whena file structure other than the VAT structure is used, the effect ofavoiding concentration of data rewrite on a disc, to which the number oftimes of data rewrite is limited, is provided as far as the entry sectornumber recorded in the recording information zone is used.

In this example, when a disc is inserted, the system records a controlfile in the basic file structure area in order to recognize theinformation recorded in a plurality of AV files. In the case where onlythe file recorded on the disc need be recognized, it is not necessary torecord the control and the file entry thereof in the basic filestructure area. Then, the basic file structure area is smaller and thusthe reading time is shortened. In the case where the basic filestructure area is recorded within one ECC block as the minimum readingunit, the driving device performs data read only once. In this manner,an information recording medium according to the present inventioncauses the data to be updated or recorded including the latest filestructure area to be moved from an inner portion to an outer portion.Therefore, data destruction or defect due to concentration of datarewrite is prevented and data reliability can be improved.

2. EXAMPLE 2

In Example 2, a method for sequentially recording an AV file in the AVfile area pre-allocated in the volume space and a defect managementmethod of information recorded in the latest file structure area will bedescribed.

AV data to be recorded in the AV file area needs to be recordedcontinuously time-wise, and thus is recorded without verify. Filemanagement information, such as the file set descriptor, and a controlfile are required to be reliable and thus is recorded with verify so asto guarantee the data reliability at the time of recording. In general,an AV file has a large data size, whereas a control file or filemanagement information have a small file size. AV data and non-AV datathus have different characteristics. An example in which an area usedfor recording AV data and an area used for non-AV data are separatedwill be described.

In the case where unallocated areas are managed in a table form as inExample 1, sequential recording is performed by defining the order inwhich management information in the unallocated areas is registered. InExample 2, unallocated areas are managed using an improved bit map whichis recorded in the space management structure area, and sequentialrecording is performed in the AV file area in the volume space.

In the following description, a descriptor, a pointer and the like whichare recorded on the information recording medium as a volume filestructure have a data structure defined by the ECMA167 or UDF (UniversalDisk Format) Standards unless otherwise described in detail.

2.1 Data Structure of the Optical Disc

FIG. 11 shows an exemplary data structure of the optical disc 235.

The volume space has a volume structure area 101, a sparable filestructure area 1303, and an AV file area 1308 pre-allocated at fixedpositions thereof. The sparable file structure area 1303 includes aspace management structure area 1306 in a part of the latest filestructure area. In the space management structure area, an improved bitmap is to be recorded.

A bit map is a map showing a recording state of each of areas of acertain unit, such as a sector or an ECC block. The recording state ofeach of areas of a certain unit is indicated by 0 in the case of anunrecorded state and by 1 in the case of a recorded state. A collectionof bits showing the recording states of all the sectors is referred toas a bit map. In Example 2, a bit map shows a recording state of a unit.An advantage of performing management of unallocated areas with a bitmap is that since the unallocated areas are designated using a bit foreach of areas to be managed, the size of the bit map is fixed.

A “unit” is a unit for managing recording including one or more sectors.In this example, one unit includes about 5000 sectors.

The lead-in area has a recording information zone 111 allocated thereto.The recording information zone 111 includes a spare designationinformation area 1302 including a spare unit number 1310 and spare areaaddress information 1311. In the spare designation information area, alatest file structure area 1304 is substituted for by a sparable area1307 of the sparable file structure area 1303 or other units. Thus, whendata rewrite is concentrated in the latest file structure area 1304 ofthe sparable file structure area 1303 or when the entire area becomesunrecordable, such substitution prevents the medium from becomingunrecordable entirely. As a result, data can be recorded in the latestfile structure area.

2.2 File Recording Processing

FIG. 13 shows a procedure of file recording processing for recording afile on the optical disc 235. The file recording processing is performedby the information recording and reproduction apparatus shown in FIG. 2.Hereinafter, the steps shown in FIG. 13 will be described in detail.

(S1501) The system control section 201 acquires a start unit number 1330from the leading end of the improved bit map 1313 which has been readinto the space management structure memory 253. The above-describedoperation of the system control section 201 is achieved by, for example,executing a control program built in the system control section 201 asthe space management structure recording means 251.

(S1502) The system control section 201 instructs the optical disc drivedevice 205 to record the AV file (AVfile-d) 146 sequentially from unit#40 designated by the start unit number 1330. The above-describedoperation of the system control section 201 is achieved by, for example,executing a control program built in the system control section 201 asthe file recording means 213.

(S1503) The system control section 201 updates the file structureincluding management information of the recorded AV file (AVfile-d), andinstructs the optical disc drive device 205 to record the updated filestructure in the latest file structure area 1304. The above-describedoperations of the system control section 201 are achieved by, forexample, executing a control program built in the system control section201 as the basic file structure recording means 261.

At this point, when a write error is returned from the optical discdrive device 205 for the reason that the latest file structure area 1304of the sparable file structure area 1303 becomes unrecordable due toconcentration of data rewrite, scratches or dust, the system controlsection 201 updates the basic file structure so as to change therecording position and issues an instruction that the recording shouldbe performed in the sparable area 1307.

When another write error is returned from the optical disc drive device205 for the reason that the sparable area 1307 becomes unrecordable dueto concentration of data rewrite, scratches or dust, the system controlsection 201 issues an instruction that a basic file structure areashould be recorded in which the recording position is changed to unit#56. In this manner, unit #56, which is the next recording start unitfor performing recording sequentially in the AV file area 1308, can beused as a sparable file structure area. In this manner, when a writeerror occurs while data is being recorded in the latest file structurearea, the data recorded in the latest file structure area is updated andrecorded in an unrecorded sparable area. When there is no unrecordedarea in the sparable area, the start unit number is used to allocate asparable file structure area to an unallocated unit, and data recordedin the latest file structure area is updated and recorded at the leadingend of the sparable file structure area. When the sparable filestructure area is allocated to the unallocated unit, a predeterminedsize of sparable area is arranged in an unrecorded state. Therefore,even when a write error occurs while data is being recorded in thelatest file structure area, spare recording is realized.

The drive control section 232 instructs the recording and reproductionmeans 234 to record the basic file structure in unit #56. When therecording is completed, “56” is recorded in a spare unit number 1410 inthe recording information zone 111 in the lead-in area, and the addressinformation of the latest file structure area is recorded in spare areaaddress information 1411. Then, the drive control section 232 notifiesthe system control section 201 of completion of the processing.

(S1504) The system control section 201 creates an improved bit map 1412reflecting the state of an unallocated area of the disc, and records theimproved bit map 1412 in a space management structure area 1403. Theabove-described operations of the system control section 201 areachieved by, for example, executing a control program built in thesystem control section 201 as the space management structure recordingmeans 251.

At this point, the unit number of 57 which indicates the firstunallocated area after the recorded unit is registered as the start unitnumber at the leading end of the improved bit map. By this processing,the bits of units #40 through #56, which indicate the recording statesof these units having data recorded therein, are changed to “1”, whichindicates “recorded”.

FIG. 12 shows a structure of data recorded on the optical disc 235 afterthe file recording processing is performed on the optical disc 235having the data structure shown in FIG. 11.

In this example, the second cycle of the sequential recording performedin an inner portion to an outer portion in the AV file area isdescribed. In an information recording medium to which the number oftimes of data rewrite is limited, the recording start position isdesignated by a start unit number. Therefore, sequential recording canbe performed repeatedly in the AV file area, from an inner portion to anouter portion of the disc.

The next recording start position may be designated by an addressinstead of a start unit number. When the next recording start positionis designated by an address, the recording start position can bedesignated in more detail as compared to the case of using a start unitnumber. Instead of the next recording start position, the previousrecording end position may be designated.

In this example, the unallocated areas in which AV files can be recordedare designated unit by unit, and the areas in which the AV files arerecorded are designated logical sector by logical sector. Forsimplification, the areas in which the AV files are recorded may also bedesignated unit by unit.

In this example, only the AV files are recorded in the AV file area. Asdescribed in Example 1, a file entry of the AV file may also be recordedin the AV file area.

In the case where the size of the control file is excessively large orthe number of control files is excessively large, the control file(s)and file entry (entries) thereof may be recorded in the AV file area. Inthis manner, data rewrite is prevented from concentrating in a specificarea when the control files are updated.

For recording data in the volume structure area and the latest filestructure area, recording with verify is performed. For recording datain the AV file area, recording without verify is performed. “Recordingwith verify” refers to a recording method by which it is confirmed thatdata can be read after the recording is performed. “Recording withoutverify” refers to a recording method by which it is not confirmed thatdata can be read after the recording is performed.

In this example, the latest file structure area after substitution ismanaged by the system control section 201. In a system in which thespare area is managed by the drive control section 231, the managementmay be performed by a system referred to as “linear replacement”.“Linear replacement” refers to a system by which the drive controlsection manages the correspondence between logical address informationdesignated by the system control section and physical addressinformation of the address at which data is actually recorded. By thissystem, reproduction is performed not by accessing the indicated logicaladdress but by reading data from the corresponding physical address. Inthis system, the system control section need not update the recordingposition information for the basic file structure in accordance with thesubstitution.

In the case where two-stage substitution processing is performedincluding substitution by a sparable area and allocation of a sparablefile structure area to a unit, even when the number of data rewriteunexpectedly increases in a medium having a defined size of filestructure area or AV file area, recording to and reproduction from themedium can be performed without interruption.

2.3 File Reproduction Processing

FIG. 14 shows a procedure of file reproduction processing forreproducing a file recorded on the optical disc 235. The filereproduction processing is performed by the information recording andreproduction apparatus shown in FIG. 2. Hereinafter, the steps shown inFIG. 14 will be described in detail. In the following example, the AVfile (AVfile-d) 158 is reproduced from the optical disc 235 having thedata structure shown in FIG. 12.

(S1601) When an optical disc is inserted to the optical disc drivedevice 205, the drive control section 231 reads a spare unit number 1410and spare area address information 1411 from the spare designationinformation area 1302 of the recording information zone, and notifiesthe system control section 201 of the spare unit number 1410 and thespare area address information 1411. The above-described operations ofthe system control section 201 are achieved by, for example, executing acontrol program built in the system control section 201 as theinformation recording and reproduction means 272.

The system control section 201 determines whether the read spare unitnumber 1410 is 0 or 1. When the number is 0, the processing advances tostep (S1603). Otherwise, the processing advances to step (S1602).

(S1602) The system control section 201 reproduces a basic file structurefrom a basic file structure area of the latest file structure arearecorded in a unit having the designated unit number, based on the spareunit number and the spare area address information.

In the example shown in FIG. 12, the spare unit number 1410 is 56.Accordingly, a basic file structure is read from a basic file structurearea 1402 of a latest file structure area 1401 recorded in unit #56.

(S1603) The system control section 201 reproduces a basic file structurefrom a basic file structure area of the latest file structure arearecorded in a pre-allocated sparable file structure area, based on thespare address information.

In the example shown in FIG. 11, the spare unit number 1410 is 0.Accordingly, a basic file structure is read from a basic file structurearea 1305 of the latest file structure area 1304 recorded in thesparable file structure area 1303.

The operations of the system control section 201 described in steps(S1602) and (S1603) are achieved by, for example, executing a controlprogram built in the system control section 201 as basic file structurereproduction means 262.

(S1604) The system control section 201 decodes the basis file structureand reproduces the intended AV file (AVfile-d) 158. The above-describedoperations of the system control section 201 are achieved by, forexample, executing a control program built in the system control section201 as file reproduction means 216.

In general, the size of AV files is larger than the size of controldata. Therefore, in this example, the AV files are managed unit by unit.Accordingly, the recording position information of an AV file can beeasily designated using a unit number instead of a logical sectornumber.

In this example, unallocated areas are registered in the bit map in theorder from an inner portion to an outer portion of the disc.Accordingly, sequential loop recording can be performed by designatingthe next recording position with a start unit number. By the method ofmanaging unallocated areas using a table as shown in Example 1,unallocated areas are registered in the table in the order from an innerportion to an outer portion of the disc, and the next recording startposition is designated by an entry sector number.

In Example 2, the sparable file structure area is pre-allocated in thevolume space. Therefore, data rewrite of the latest file structure isconcentrated. However, the spare designation information area includingthe recording information zone allows data to be recorded at a differentlocation. As a result, the medium is prevented from becoming entirelyunusable.

By use of a start unit number provided in the improved bit map which isrecorded in the space management structure area, a recording startposition in the AV file area can be acquired. This allows the AV filesto be recorded sequentially while avoiding concentration of datarewrite. In the case where the start unit number is registered at theleading end of the space management structure, recording can be startedfrom the recording start position immediately after the space managementstructure is acquired.

In Example 1, data is sequentially recorded in the latest file structurearea. In Example 2, data is rewritten in the latest file structure areaeach time the data is updated. Recording of the latest file structurearea may be performed sequentially and repeatedly in the sparable filestructure area, using, as described in Example 1, empty area informationrecorded in the space management structure area and spare addressinformation which indicates the position allocated as the latest filestructure area. For example, recording may be performed in the followingmanner for updating data. Up to the trailing end of the sparable filestructure area, an unallocated area is searched for in a certaindirection (for example, from an inner portion to an outer portion of thedisc) from a position continuous from the position of the area to whichthe latest file structure area is allocated (i.e., the positionindicated by the pointer information). The area is allocated based onthe search result, and data of the latest file structure area isrecorded in the allocated area. In the case where the latest filestructure area is recorded at the trailing end of the sparable filestructure area, an unallocated area is searched for in a certaindirection from the leading end of the sparable file structure area. Thearea is allocated based on the search result, and data of the latestfile structure area is recorded in the allocated area.

As can be understood, the sparable file structure area is structuredsuch that another area (for example, the latest file structure area) canbe allocated to a part of the sparable file structure area. Thedifferent area (for example, the latest file structure area) allocatedto the part of the sparable file structure area is structured so as tobe movable in the sparable file structure area. Thus, data can berecorded repeatedly in a certain direction such that latest filestructure areas are distributed throughout the sparable file structurearea.

In Example 2, sequential loop recording can be performed both in the AVfile area and the sparable file structure area. Thus, concentration ofdata rewrite in any specific area throughout the disc is avoided. Bydividing an area into a plurality of areas and performing sequentialloop recording in each of the divided areas, data reliability can beimproved and the reading speed of an intended file can be raised.

3. EXAMPLE 3

In Example 3, AV files are sequentially recorded in the AV file area,using a table for simultaneously managing the recording position of afile and the position of an unallocated area, such as a FAT file systemapplied to a hard disc or the like.

When constructing a system compatible with a hard disc, the hard discand the optical disc can be handled by one file system by introducingthe FAT file system to the optical disc.

In the following description, a descriptor, a pointer and the like whichare recorded on the information recording medium as a volume filestructure have a data structure defined by the ECMA167 or UDF (UniversalDisk Format) Standards unless otherwise described in detail.

3.1 Data Structure of the Optical Disc

FIG. 15 shows an exemplary data structure of the optical disc 235.

The volume space has a system area 1701, a latest file structure area1702, and an AV file structure area 1703.

The latest file structure area 1702 includes a FAT (File AllocationTable) area 1704, a root directory area 1705, an AV directory area 1706,and a data file area 1707. In the FAT area 1704, FAT is recorded, whichhas chain information on the recording positions of directories andfiles and information on the recording state of clusters.

The FAT is a table in which cluster recording information havingrecording information for each of clusters is recorded. The number ofpieces of cluster recording information recorded corresponds to thenumber of clusters. In a directory entry recorded in the root directoryarea 1705 and an AV directory area 1706, start cluster numbers of thedirectory and the file are registered. In the example shown in FIG. 15,a directory entry (AVfile-a) 1713 has start cluster number 1 of an AVfile (AVfile-a) 144. The FAT chain information includes cluster #1 as astart cluster of the AV file (AVfile-a) and cluster number 2, which isthe number of the next cluster, registered thereto. In this manner, theAV file (AVfile-a) is reproduceable by following the chain information.In the “value” section of the chain information, “EOF” indicates thetrailing end of the file and is, for example, FF8 (hexadecimal).

A cluster is a unit for recording management including one or moresectors. In this example, one cluster includes about 5000 sectors.

3.2 File Recording Processing

FIG. 16 shows a procedure of file recording processing for recording afile on the optical disc 235. The file recording processing is performedby the information recording and reproduction apparatus shown in FIG. 2.Hereinafter, the steps shown in FIG. 16 will be described in detail.

(S1801) The system control section 201 reads a FAT from the FAT area1704 at the leading end of the latest file structure area 1702, searchesfor a cluster number marked as starting point information, andsequentially acquires information on unallocated areas from the markedcluster number in an ascending order. The above-described operations ofthe system control section 201 are achieved by, for example, executing acontrol program built in the system control section 201 as the spacemanagement structure recording means 251.

(S1802) The system control section 201 sequentially records AV filesfrom the designated starting point cluster. The above-describedoperation of the system control section 201 is achieved by, for example,executing a control program built in the system control section 201 asthe file recording means 213.

(S1803) The system control section 201 records, in the latest filestructure area, the AV directory area including the information on therecorded AV file, the root directory area, the data files, and the FATarea. In the FAT recorded at this point, the cluster information, havingthe chain information and the starting point information of the recordedfiles, is updated. For example, in FIG. 15 showing the data structureafter the AV file (AVfile-c) 146 is recorded, the next recordingstarting point is cluster #56. Therefore, “1” is registered as thestarting point information of the cluster #56 of the FAT 1710. Theabove-described operations of the system control section 201 areachieved by, for example, executing a control program built in thesystem control section 201 as the basic file structure recording means261.

In this example, the second cycle of the sequential recording performedin an inner portion to an outer portion in the AV file area isdescribed. In an information recording medium to which the number oftimes of data rewrite is limited, sequential loop recording is performedin a similar manner in the AV file area in the first and subsequentcycles.

For simplicity of explanation, the control file, which is a data file,is recorded as a part of the latest file structure area. The controlfile is not supplied with any cluster number and is managed by thelogical sector number. Alternatively, a data file may be recorded in thecluster in the AV file area as a data file for controlling theinformation of an AV file.

In Example 3, the AV directory area, the root directory area, the datafiles, and the FAT area are recorded in the latest file structure areain accordance with the basic file structure recording means 261. The FAThas a structure having a function of a space management structure, butalso performs file management. Therefore, the FAT is handled by thebasic file structure recording means and the basic file structurereproduction means.

In Example 3, the starting point information for performing sequentialrecording is recorded with bit 1. It is clear that the starting pointinformation may be indicated with other values such as FFh.

In Example 3, the start position of sequential recording can be acquiredalso using a data structure, such as a FAT, in which the information onunallocated areas and the chain information of files are managed by thesame table. In this case also, AV files can be sequentially recordedwhile avoiding concentration of data rewrite in the AV file area.

In Example 2, the start unit number is registered at the leading end ofthe space management structure. In Example 3, the starting pointinformation is registered as a part of the information on each clusterin the space management structure. In the case where the starting pointinformation is registered in reserved bytes of information on eachcluster, this file system can be compatible with existing computeroperating systems without extending the FAT Standards.

The two-stage defect management method described in Example 2 isapplicable to the latest file structure area including the FAT area inthis example.

The cluster, which becomes unusable due to occurrence of a defect in theAV file area, may be registered in the FAT 1710 in the FAT area 1704. Inthis case, FFh is registered as, for example, the value of the startingpoint information.

4. EXAMPLE 4

In Example 4, an exemplary defect management method when an AV file, acontrol file, and a volume file structure are sequentially recorded on adisc to which the number of times of data rewrite is limited will bedescribed.

Even in the case where, as in Example 1, occurrence of a defect area isprevented by avoiding concentration of data rewrite in a specific areausing sequential recording, the number of defect areas increases as thedisc is used an increasing number of times.

In the following description, a defect area includes an area in whichdata cannot be recorded or reproduced, and a minimum unit thereof is 1ECC block.

4.1 Data Structure of the Optical Disc

FIG. 17 shows an exemplary data structure of the optical disc 235.

The volume space includes defect areas 1902, 1906, 1906 and 1910. Adefect list structure area 1908 is allocated in which these defect areasare to be registered. In the defect list structure area 1908, a systemstream directory 1923 in which a data structure for the system is to beregistered, a file entry 1924 thereof, and a file entry 1925 of anon-allocatable space stream are recorded. The non-allocatable spacestream is a data structure defined for registering a defect area or anarea in which a volume file structure cannot be allocated. In thisexample, the non-allocatable space stream is used for registering thepositional information of a defect area.

FIG. 18 shows a procedure of file recording processing for recording afile on the optical disc 235. The file recording processing is performedby the information recording and reproduction apparatus shown in FIG. 2.Hereinafter, the steps shown in FIG. 18 will be described in detail. Inthe following example, the AV file (AVfile-c) is recorded on the opticaldisc 235 having the data structure shown in FIG. 17.

(S2001) The system control section 201 records the AV file (AVfile-c) inunallocated areas sequentially from the unallocated area having thedesignated entry sector number. When the defect area 1906 is detectedwhile recording the AV file, the system control section 201 skips thedefect area and continues the recording in the next unallocated area.Accordingly, the areas in which the AV file is actually recorded are afirst extent 1921 of an AV file area 1905 and a second extent 1922 of anAV file area 1907. The above-described operation of the system controlsection 201 is achieved by, for example, executing a control programbuilt in the system control section 201 as the file recording means 213.

(S2002) The system control section 201 creates a file entry (AVfile-c)147 having positional information of the first extent 1921 and thesecond extent 1922 (in which the AV file (AVfile-c) is recorded)registered therein. The system control section 201 then stores the fileentry (AVfile-c) 147 in the basic file structure memory 235 of thememory circuit 263.

(S2003) The system control section 201 records a control file (Datafile)148 on a subsequent unallocated area. When a defect area is detectedwhile recording the control file, the system control section 201 skipsthe defect area and continues the recording in the next unallocatedarea, like in the case of the recording of the AV file described in step(S2001).

(S2004) The system control section 201 creates the file entry (Datafile)149 in which the positional information of the area (extent), in whichthe control file (Datafile) 148 is recorded, is registered. The systemcontrol section 201 then stores the file entry (Datafile) 149 in thebasic file structure memory 235 of the memory circuit 263. In the casewhere the control file is recorded in a plurality of extents due to adefect area being detected, all the extent position information isregistered when the recording position information of the control fileis registered, like in the case of the AV file.

(S2005) The system control section 201 creates a system stream directory1924, which is a defect list structure, and the file entry 1923 thereof,and also creates the file entry 1925 of an allocated space stream inwhich the positional information of a defect area detected in the volumespace is registered. The system control section 201 stores the fileentry 1925 in the basic file structure memory 235.

In addition, the system control section 201 creates the unallocatedspace entry 1925 in which positional information of the unallocatedspace is registered, excluding the unallocated areas recorded in thefile recording processing and positional information of the defect areasdetected in the file recording processing. The system control section201 then stores the unallocated space entry 1925 thereof in the basicfile structure memory 235.

Concurrently, the system control section 201 creates the AV directory(AVDir) 150 including information of the recorded AV file and thecontrol file, the file set descriptor 152, the root directory 153, thefile entry 154 of the root directory, the file entries 145 and 159 inwhich positional information and attribute information of recorded AVfiles (AVfile-a) 144 and (AVfile-d) 158 are registered, the VAT 156, andthe VATICB 157. The system control section 201 stores these data in thebasic file structure memory 235.

(S2006) The system control section 201 records the basic file structure,the defect list structure, the space management structure 123 and theVAT structure, which are created in steps (S2002), (S2004) and (S2005),in the latest file structure area 131.

(S2007) In the case where a defect area is detected while data is beingrecorded in the latest file structure area 131, the processing of steps(S2008) et seq. is executed. When the recording is completed with nodefect being detected, the file recording processing is terminated.

(S2008) The system control section 201 updates the defect list structureand the registration information on the space management structure. Inthe non-allocatable space stream which is a defect list structure,positional information on a newly detected defect area is registered.From the non-allocatable space stream which is a space managementstructure, the positional information on a newly detected defect area iseliminated.

(S2009) The system control section 201 designates the subsequentunallocated area in order to record data in the updated latest filestructure.

The operations of the system control section 201 described in steps(S2001) through (S2009) are achieved by, for example, executing acontrol program built in the system control section 201 as the basicfile structure recording means 261.

In the recording processing of the AV file in this example, an area,from which an error report is returned for the reason that the recordingcannot be completed while recording is performed without verify, isidentified as a defect area.

In general, data to be recorded in the volume structure area and thelatest file structure area is recorded with verify, and data to berecorded in the AV file area is recorded without verify. Alternatively,the data to be recorded in the AV file area may be recorded with verify.The data to be recorded in the volume structure area and the latest filestructure area may be recorded without verify. The data to be recordedin the AV file area may be recorded with recognition that there is nodefect area, in order to save the time required for substitutionprocessing. In this case, a defect area is distinguished at the time ofreproduction of the file.

In order to change the defect management method in accordance with thecharacteristics of the file, an area used for recording data to whichone defect management method is applied, and an area used for recordingdata to which a different defect management method is applied, may beseparated from each other.

An area from which the file cannot be reproduced may also be registeredas a defect area.

The positional information of a defect area registered as anon-allocatable space stream is used for re-formatting the medium.Accordingly, it is necessary to maintain the content of thenon-allocatable space stream until the medium is re-formatted.

The positional information of the detected defect area may be recordedoutside the volume space. For example, such positional information maybe managed in the registration block of the recording information zonein Example 1.

The method described in this example may be applied to Example 3. Whenperforming defect management, data is recorded while a defect area beingskipped, and defect information is registered in the FAT.

As described above, in this example, while sequential recording on arewritable medium is repeated, recording in the subsequent area can beperformed while avoiding a detected defect area without substitution.Thus, in the case of a rewritable recording medium in which the amountof detected defects significantly changes in accordance with theconditions of use, it is not necessary to obtain a spare area in advanceor to extend the spare area when there is a shortage thereof. The areaof the medium can be effectively used.

5. EXAMPLE 5

In Example 5, regarding a disc to which the number of time of datarewrite is limited as a result of the density being increased, anexemplary data structure for an entry sector number used for performingsequential loop recording from an inner portion to an outer portion ofthe disc, and an exemplary update method thereof, will be described.

In this example, an entry sector number is recorded in the volume spacewhich is managed by the file system, not in the recording informationzone.

In Example 1, the recording information zone includes a count unit and aplurality of registration units, so that the reliability of the entrysector number of the disc to which the number of times of data rewriteis limited is improved.

In this example, the reliability of the entry sector number can beimproved since the data structure defined by the ECMA167 is updatedstepwise, and the recording information zone is not necessary since theentry sector number is recorded. Thus, the techniques described in thisexample is applicable to general-purpose discs.

FIG. 19 is a data structure regarding an entry sector number which isupdated and recorded in the volume structure.

A function of an entry sector number 3032 is the same as the functiondescribed in the other examples. In FIG. 19, the entry sector number3032 indicates the address of the VAT ICB 157 of the VAT structure area104 in the latest file structure area 131. The entry sector number 3032is recorded in a field saved for the processing system in a logicalvolume integrity descriptor 3031 in a logical volume integritydescriptor sequence 3011.

Recorded in the logical volume integrity descriptor is integrityinformation indicating whether or not the file structure recorded in thevolume space is in a correct state. Therefore, the reliability of theentry sector number can be further improved by recording the entrysector number in the logical volume integrity descriptor.

Positional information of the logical volume integrity descriptorsequence 3011 is recorded in a logical volume descriptor 3022 in avolume descriptor sequence 3010. The volume descriptor sequence 3010 isprovided for recording a descriptor regarding a volume. A primary volumedescriptor 3021 and a partition descriptor 3023 are recorded in thevolume descriptor.

Positional information of the volume descriptor sequence 3010 isrecorded in an anchor volume descriptor pointer 3041. The anchor volumedescriptor pointer is recorded in a fixed sector at a logical sectornumber 256. Although not shown, the anchor volume descriptor pointer isalso recorded in the logical sector of N-256, where N is the logicalsector number of the outermost portion of the volume space. Since theanchor volume descriptor pointer is recorded twice, even when one of thepointers cannot be read, the other anchor volume descriptor pointer canbe used.

FIG. 20 shows a procedure for updating and recording an entry sectornumber. An update method for an entry sector number will be described.

(S3001) For the logical volume integrity descriptor sequence, an areacorresponding to, for example, 32 sectors is saved. The logical volumeintegrity descriptors are sequentially recorded from the leading end thelogical volume integrity descriptor sequence, and the final volumeintegrity descriptor recorded is recognized as a valid descriptor. Theentry sector number is updated by recording a logical volume integritydescriptor in the subsequent logical sector. When there is no moresubsequent logical sector, 00h is recorded in all the logical sectors inthe logical volume integrity descriptor sequence, and the logical volumeintegrity descriptor is recorded at the leading end of the logicalvolume integrity descriptor sequence.

(S3002) When recording a logical volume integrity descriptor, it ischecked whether or not the logical sector to be recorded is a defectsector. When it is not a defect sector, the processing is terminated.When it is a defect sector, the processing advances to step (S3003),where a logical volume integrity descriptor sequence is newly saved inan empty area in the volume structure area, so that the logical volumeintegrity descriptor is recorded.

In this manner, in the case of a disc to which data rewrite is limitedto 100 times, a logical volume integrity descriptor can be recorded32×100 times, using the same logical volume integrity descriptorsequence.

When a logical volume integrity descriptor sequence is newly allocated,it is necessary to record a logical volume descriptor for managing thepositional information of the logical volume integrity descriptorsequence.

(S3004) For the volume descriptor sequence, an area corresponding to,for example, 16 sectors is saved. The logical volume descriptor has afield indicating a volume descriptor order number. When a plurality oflogical volume descriptors are recorded in the volume descriptorsequence, the logical volume descriptor having the largest volumedescriptor order number is valid. For recording the logical volumedescriptors, empty logical sectors are searched for from the leading endof the volume descriptor sequence. The logical volume descriptors arerecorded from the leading empty logical sector. When there is no emptylogical sector, all the old logical volume descriptors are recorded with00h so as to create an empty logical sector, and then the logical volumedescriptors are recorded from the leading empty logical sector.

(S3005) When recording a logical volume descriptor, it is checkedwhether or not the logical sector to be recorded is a defect sector.When it is not a defect sector, the processing is terminated. When it isa defect sector, the processing advances to step (S3006), where alogical volume descriptor sequence is newly saved in an empty area inthe volume structure area, so that the logical volume integritydescriptor is recorded together with a primary volume descriptor and apartition descriptor.

In this manner, in the case of a disc to which data rewrite is limitedto 100 times, a logical volume descriptor can be recorded (16−2)×100times, using the same logical volume descriptor sequence.

(S3007) When a volume descriptor sequence is newly allocated, an anchorvolume descriptor pointer for managing the positional information of thevolume descriptor sequence is updated and recorded.

Since the entry sector number is updated and recorded stepwise in thismanner, recording can be performed (32×100)×((16−2)×100)×100 times intotal even on a disc to which the number of times of data rewrite islimited to 100.

The step for updating and recording may be varied in accordance with therequired number of times of data rewrite. It is clear that when 1000times of rewrite is sufficient, the entry sector number can be rewrittenin the same logical volume integrity descriptor sequence.

INDUSTRIAL APPLICABILITY

An information recording medium according to the present inventiondefines the order of use of unallocated areas registered in a spacemanagement structure, and records data while moving a latest filestructure area from an inner portion to an outer portion. Thus, datadestruction or defect due to concentration of data rewrite is preventedand data reliability can be improved.

1. An information recording medium of which the number of times of datarewrite to an identical area is limited, the information recordingmedium comprising: an information recording area to which sequentialloop recording is to be performed; and a pointer information recordingarea for recording pointer information indicating a position of an areawhich has been allocated by a previous recording operation to theinformation recording area.
 2. An information recording medium accordingto claim 1, wherein the information recording area includes an area forrecording a file structure.
 3. An information recording medium accordingto claim 1, wherein the information recording area includes an area forrecording a space management structure for managing an unallocated areain the information recording area.
 4. An information recording medium ofwhich the number of times of data rewrite to an identical area islimited, the information recording medium comprising: a firstinformation recording area to which sequential loop recording is to beperformed; a second information recording area to which sequential looprecording is to be performed; a first pointer information recording areafor recording first pointer information indicating a position of an areawhich has been allocated by a previous recording operation to the firstinformation recording area, and a second pointer information recordingarea for recording second pointer information indicating a position ofan area in which data has been recorded by a previous recordingoperation to the second information recording area, wherein the secondpointer information recording area is provided in the first informationrecording area.
 5. An information recording medium according to claim 4,wherein: the second information recording area includes an AV filerecording area for recording an AV file, and the first informationrecording area includes a management information area for recordingmanagement information for managing the AV file recording area.
 6. Aninformation recording medium according to claim 5, wherein a defect areain the management information area is managed in accordance with a firstdefect management method, and a defect area in the AV file recordingarea is managed in accordance with a second defect management methodwhich is different from the first defect management method.
 7. Aninformation recording medium according to claim 6, wherein the firstdefect management method is based on recording with verify, and thesecond defect management method is based on recording without verify. 8.An information recording medium according to claim 4, wherein: thesecond information recording area includes an AV file recording area forrecording an AV file, and the first information recording area includesa non-AV file recording area for recording a non-AV file.
 9. Aninformation recording medium of which the number of times of datarewrite to an identical area is limited, the information recordingmedium comprising: a first information recording area to whichsequential loop recording is to be performed; and a second informationrecording area, allocated to a part of the first information recordingarea, to which sequential loop recording is to be performed, wherein theinformation recording medium is structured so as to allow a position ofthe second information recording area to be moved in the firstinformation recording area.
 10. An information recording method forrecording information on an information recording medium of which thenumber of times of data rewrite to an identical area is limited, theinformation recording medium including an information recording area towhich sequential loop recording is to be performed, and a pointerinformation recording area, the information recording method comprisingthe steps of: performing a recording operation to the informationrecording area repeatedly; and recording, in the pointer informationrecording area, pointer information indicating a position of an areaallocated by a previous recording operation to the information recordingarea.
 11. An information recording method according to claim 10, furthercomprising the step of searching for an unallocated area in theinformation recording area in a certain direction from a positionsubsequent to the position indicated by the pointer information.
 12. Aninformation recording method for recording information on an informationrecording medium of which the number of times of data rewrite to anidentical area is limited, the information recording medium including afirst information recording area to which sequential loop recording isto be performed, a second information recording area to which sequentialloop recording is to be performed, a first pointer information recordingarea, and a second pointer information recording area, wherein thesecond pointer information recording area is provided in the firstinformation recording area, the information recording method comprisingthe steps of: performing a recording operation to the first informationrecording area repeatedly; recording, in the first pointer informationrecording area, first pointer information indicating a position of anarea allocated by a previous recording operation to the firstinformation recording area; performing a recording operation to thesecond information recording area repeatedly; and recording, in thesecond pointer information recording area, second pointer informationindicating a position of an area in which data has been recorded by aprevious recording operation to the second information recording area.13. An information recording method according to claim 12, furthercomprising the steps of: searching for an unallocated area in the firstinformation recording area in a certain direction from a positionsubsequent to the position indicated by the first pointer information;and searching for an unallocated area in the second informationrecording area in a certain direction from a position subsequent to theposition indicated by the second pointer information.
 14. An informationrecording method for recording information on an information recordingmedium of which the number of times of data rewrite to an identical areais limited, the information recording medium including a firstinformation recording area to which sequential loop recording is to beperformed, and a second information recording area to which sequentialloop recording is to be performed, the information recording methodcomprising the steps of: allocating the second information recordingarea to a part of the first information recording area; and moving aposition of the second information recording area, allocated to the partof the first information recording area, in the first informationrecording area.
 15. An information recording apparatus for recordinginformation on an information recording medium of which the number oftimes of data rewrite to an identical area is limited, the informationrecording medium including an information recording area to whichsequential loop recording is to be performed, and a pointer informationrecording area, the information recording apparatus comprising: meansfor performing a recording operation to the information recording arearepeatedly; and means for recording, in the pointer informationrecording area, pointer information indicating a position of an areaallocated by a previous recording operation to the information recordingarea.
 16. An information recording apparatus according to claim 15,further comprising means for searching for an unallocated area in theinformation recording area in a certain direction from a positionsubsequent to the position indicated by the pointer information.
 17. Aninformation recording apparatus for recording information on aninformation recording medium of which the number of times of datarewrite to an identical area is limited, the information recordingmedium including a first information recording area to which sequentialloop recording is to be performed, a second information recording areato which sequential loop recording is to be performed, a first pointerinformation recording area, and a second pointer information recordingarea, wherein the second pointer information recording area is providedin the first information recording area, the information recordingapparatus comprising: means for performing a recording operation to thefirst information recording area repeatedly; means for recording, in thefirst pointer information recording area, first pointer informationindicating a position of an area allocated by a previous recordingoperation to the first information recording area; means for performinga recording operation to the second information recording arearepeatedly; and means for recording, in the second pointer informationrecording area, second pointer information indicating a position of anarea in which data has been recorded by a previous recording operationto the second information recording area.
 18. An information recordingapparatus according to claim 17, further comprising: means for searchingfor an unallocated area in the first information recording area in acertain direction from a position subsequent to the position indicatedby the first pointer information; and means for searching for anunallocated area in the second information recording area in a certaindirection from a position subsequent to the position indicated by thesecond pointer information.
 19. An information recording apparatus forrecording information on an information recording medium of which thenumber of times of data rewrite to an identical area is limited, theinformation recording medium including a first information recordingarea to which sequential loop recording is to be performed, and a secondinformation recording area to which sequential loop recording is to beperformed, the information recording apparatus comprising: means forallocating the second information recording area to a part of the firstinformation recording area; and means for moving a position of thesecond information recording area, allocated to the part of the firstinformation recording area, in the first information recording area.